This study aims to propose a rational reconstruction of the theory-core ofWittgenstein's Tractatus, in order to bring into prominence its theoreticaland philosophical sources, its epistemological nature and metaphysical significance.The main idea of my approach is that when we take due account of the scientific andphilosophical context of the Tractatus, we see that its central philosophicalinnovation is a new form of metaphysics, namely a structural theory of representation.``I am not interested in constructing a building,so much as in having a perspicuous view of the foundation of possible buildings.''.